This application addresses broad Challenge Area (04) Clinical Research and specific Challenge Topic, 04- MH-105: Conduct pilot studies to develop and test developmentally appropriate, evidence-based prevention interventions and service delivery models for youth with who are at high risk for, or experiencing severe mental illnesses who are transitioning to adulthood. As they move into adulthood transition age youth (TAY;ages 17-25) with serious mental health conditions have alarmingly poor functioning;high rates of homelessness (30%), arrests (60%), school dropout (42%), and unemployment (see1). These problems could be reduced by good mental health (MH) treatment. However, among adults who seek MH care, TAY are consistently the most likely to drop out of treatment (e.g.2), and they complete the fewest number of sessions among those older or younger.3 There is no MH treatment without treatment retention (TR). A simple and potentially cost-effective step to improving TAY functioning is to develop effective TR interventions for the most commonly used MH treatment;office-based outpatient psychotherapy.4 There are currently no clinical trials underway or published TR interventions for TAY. The proposed study develops and pilots a new TR intervention for office-based outpatient psychotherapy tailored for TAY, and pilot tests an existing intervention not yet examined in this age group. Though the specific causes of treatment dropout in TAY have not been investigated, they are likely manifold. Multiple causes of treatment dropout have been identified in adults5 with no predominant factor emerging from the research. Mature adults and TAY likely share some causes of premature termination, but because of the unique developmental and life stage features of the transition period (see6) it is unlikely that successful TR interventions in adults are as effective with TAY. Some of the unique developmental characteristics that can contribute to compromised TR in TAY include: " Age-typical rejection of authority that can interfere with therapeutic relationships, and immature cognitive development that can interfere with the abstract task of therapeutic goal-setting " Immature responsibility-taking that may interfere with attending sessions and embracing the work of therapy, especially since parental influence diminishes during the transition to adulthood " The stigma of needing mental health treatment is keenly felt because of the centrality of peer acceptance and pursuit of romantic relationships at these ages, and may reduce TR. The proposed research will begin the work of testing Motivational Interviewing (MI)7 as a TR intervention in TAY. MI is a widely used intervention to enhance motivation and reduce ambivalence about change, that has increased treatment adherence in older and younger age groups. MI is additionally appealing because it can readily be added to standard therapy. In addition, a second TR intervention will be developed that targets mechanisms of TR that are likely unique to TAY and are different than those targeted in MI. The proposed research undertakes the initial steps towards determining the efficacy of these two approaches in increasing TAY TR. The research will initiate development and feasibility assessment of the developmentally tailored TR intervention, and feasibility of the research design to pilot test both TR interventions in comparison to "services as usual." It is the preliminary step to determine whether sufficient evidence can be found to justify a full scale clinical trial. The two TR interventions are: " Peer Therapy Coach (PTC);this web-based peer intervention that focuses on supporting participation in outpatient psychotherapy will be developed in the proposed research " Motivational Interviewing (MI);this therapist-implemented intervention has been used to increase treatment adherence among adults and adolescents in addictions, health, and MH treatment, but has not specifically been tested as a TR strategy in transition age youth. Aim 1. Specify implementation and training protocols and a fidelity measure for a new outpatient MH psychotherapy TR intervention (PTC). Aim 2. Determine the feasibility of the PTC approach and randomized clinical trial research design comparing Motivational Interviewing and PTC to services as usual. This research will jump start progress towards retaining more transition age youth in widely used treatments by simultaneously developing a tailored TR intervention and testing a successful one not tried in this age group. It will be consistent with the President's Recovery and Reinvestment Act by putting 97% of its direct cost budget towards personnel, and providing jobs for youth with psychiatric disabilities. Youth with mental health needs during the transition to adulthood have tremendously compromised functioning in working, living independently, and staying out of trouble with the law. Office-based mental health treatment is accessed by 760,000 transition age youth (ages 17- 25) each year, but the impact of this widely available treatment is compromised in this age group because they are particularly prone to drop out of treatment. If the two promising treatment dropout prevention interventions pilot tested in the proposed research are successful, more transition age youth in the future will remain in treatment long enough for it to have its beneficial impact on symptoms and by extension, functioning.